1. Field of the Invention
The present invention relates to an apparatus that facilitates the fast and easy installation or removal of a removable computer component into or out of a computer. More particularly, the present invention relates to a pawl latching and retaining device for retaining and releasing a removable disk drive in a computer. The removable computer component may otherwise be floppy disk drives, optical disk drives and the like.
2. Description of Related Art
Mass storage devices including so called Hard Disk Drives are commonplace components of modern personal computers. As these devices have a far higher storage capacity than the standard Floppy Disk Drive, transferring a substantial fraction of the data capacity of a hard disk from one computer to another via floppy disks is impractical. This poses problems for computer users who may need access to the data on a hard disks on different computers at different locations.
On the other hand, in offices where there are fewer computers than personnel, so that the computer users must share a single computer, it is desirable to provide a computer system where the data is interchangeable for each user. In situations involving security information, it is particularly important that the data is not available to others, and therefore, the removal of the disk drives may be desirable.
Thus, an existing solution to these problems is to make the disk drive removable, whereby one disk drive can be exchanged between different computers or different disk drives can be exchanged by different users of a single computer. Advantages of an easily removable disk drive include easy exchange of databases on a given computer, improved data security because the drive can be removed and stored in a physically secure location, and also easy removal to facilitate repair and service of the disk drive. Also, there is no need to manually disconnect any of the cables prior to removal if appropriate electrical disconnects are incorporated into the design.
Additionally, such removable disk drive systems are a means for efficiently utilizing expensive disk drives. To illustrate, a user may have several computers each lacking an expensive, specialized disk drive. But with a single removable disk drive, all of the computers can be served by such a removable drive as needed.
A number of systems that facilitate the installation and/or removal of disk drives are known in the art. U.S. Pat. Nos. 4,633,350 and 4,912,580 to Hanson and U.S. Pat. No. 4,979,909 to Andrews disclose two such systems. In Hanson, the drive is held in a carrier module which is manually inserted into a receiving unit mounted in the computer. The force of insertion engages connectors which link the drive to the computer. Removal is accomplished by simply pulling the drive out by a handle. Similarly, Andrews features fully manual insertion and extraction, but adds a barb-like engagement member attached to a side member which is mounted on the drive. The barb engages a support frame, which is mounted in the computer, to hold the drive in place. The barb can be released by turning a lever which in turn presses the barb back away from the frame.
U.S. Pat. No. 4,982,303 to Krenz provides a different mechanism for locking the drive in place. Krenz features a latch mounted across the face plate of the drive. A handle turns a gear which mates with an internal sector gear which is part of a lever member that also features a tongue. When the handle is pushed toward the drive face, the tongue moves in the opposite direction. The tongue is positioned to engage a side of a channel member, whereby contact between the tongue and the front side of the channel cause the drive to lock in place when the handle is depressed. Similarly, when the handle is pulled, the tongue engages the rear side of the channel to help break the connection between drive and computer.
Pawl latches have typically been used to retain circuit boards within rack mount assemblies of computers. These pawl latches are affixed to one or two corners of the circuit board and engage and latch to a portion of the rack mount when the board is fully inserted. To release the board, the pawl latch(es) is pulled forward until it disengages from the rack mount. However, these pawl latch mounts have not been adapted for use with computer components other than circuit boards, and are generally used only by trained computer service and assembly personnel, and not by general computer users. Another prior art device is believed to be distributed by Compaq. It includes a circuit board with a disk drive mounted on the circuit board. A pair of pawl latches, one disposed on each of two leading edges, are used to latch the circuit board in place in a computer housing as previously described.
U.S. Pat. No. 4,960,384 relates to a retaining and release device for computer components, such as removable hard disk drives, which comprised a retaining and release mechanism disposed in a side wall of a housing for the computer component. The device comprised a pivoting bar having a flange at one end which engaged the forward edge of the computer component and a flange near the middle of the bar which extended through the wall of the housing to lock the computer component in place. The pivoting bar at its other end is angled away from the housing so that a release mechanism which engaged the bar at its angled portion pushed the bar away from the housing which pivoted the flange to release the computer component. Thus, this device, while it functioned well, required significant space on the side of the housing for successful operation in most cases.
In copending application Ser. No. 07/734,142, in the preferred embodiment, smooth engagement and disengagement of the electrical connectors linking the data storage drive to the computer are achieved by a rack and pinion mechanism. The rack is formed into a carrier tray which itself is immovably mounted inside a data drive cavity in a computer housing. A drive sled adapted for mounting to the bottom of the data storage drive housing has a complementary pinion gear designed to mesh with the rack. A lever extends radially from the center of the pinion and is used to actuate the pinion. The drive sled has angled tracks formed into its underside that interlock with another set of angled tracks formed into the top of the carrier tray. These interlocking angled tracks facilitate alignment of the data storage drive when it is inserted into the computer, and secure the drive sled to the carrier tray. In this design, a minimum of about 3/4 of an inch is required to house the retaining and release components of the invention. Accordingly, the device does not permit close or tight stacking of multiple disk drives, with a maximum efficiency, within a constrained space. This device has been incorporated into a commercial embodiment which is presently being manufactured and sold by the assignee of the present application.
It is thus desirable to provide a computer assembly which makes more efficient use of the space underneath the disk drive or other component. It is also desirable to provide a removable disk drive that can be coupled into the housing of the computer. It is also desirable to provide a removable hard disk drive with electrical connectors that can be plugged directly into the computer. The removable disk drive unit should also have a locking mechanism which prevents the connector from being inadvertently detached from the computer. The locking mechanism should be easy to use. Because computers are sometimes subjected to shock and vibration, the sled or other retaining device which holds the removable disk drive should also be sufficiently rigid and sufficiently secured to the housing to prevent undesirable flexure.